Gary, it is a flea medication, meant for severe infestations.

It has no long-term residual activity and therefore is not effective as a longer-term flea preventative. It is usually used to kill adult fleas quickly on an infested animal to give immediate relief for a day. It is then usually followed up with some other longer-term flea preventative to prevent reinfestation.

Made by Noravtis. http://www.capstar.novartis.us/